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"... This paper concerns relationships among focus of attention, choice of referring expression, and perceived coherence of utterances within a discourse segment. It presents a framework and initial theory of centering intended to model the local component of attentional state. The paper examines intera ..."

This paper concerns relationships among focus of attention, choice of referring expression, and perceived coherence of utterances within a discourse segment. It presents a framework and initial theory of centering intended to model the local component of attentional state. The paper examines interactions between local coherence and choice of referring expressions; it argues that differences in coherence correspond in part to the inference demands made by different types of referring expressions, given a particular attentional state. It demonstrates that the attentional state properties modeled by centering can account for these differences

"... This paper has three aims: (1) to generalize a computational account of the discourse process called CENTERING, (2) to apply this account to discourse processing in Japanese so that it can be used in computational systems for machine translation or language understanding, and (3) to provide some ins ..."

This paper has three aims: (1) to generalize a computational account of the discourse process called CENTERING, (2) to apply this account to discourse processing in Japanese so that it can be used in computational systems for machine translation or language understanding, and (3) to provide some insights on the effect of syntactic factors in Japanese on discourse interpretation. We argue that while discourse interpretation is an inferential process, syntactic cues constrain this process, and demonstrate this argument with respect to the interpretation of ZEROS, unexpressed arguments of the verb, in Japanese. The syntactic cues in Japanese discourse that we investigate are the morphological markers for grammatical TOPIC, the postposition wa, as well as those for grammatical functions such as SUBJECT, ga, OBJECT, o and OBJECT2, ni. In addition, we investigate the role of speaker&apos;s EMPATHY, which is the viewpoint from which an event is described. This is syntactically indicated through the use of verbal compounding, i.e. the auxiliary use of verbs such as kureta, kita. Our results are based on a survey of native speakers of their interpretation of short discourses, consisting of minimal pairs, varied by one of the above factors. We demonstrate that these syntactic cues do indeed affect the interpretation of ZEROS, but that having previously been the TOPIC and being realized as a ZERO also contributes to the salience of a discourse entity. We propose a discourse rule of ZERO TOPIC ASSIGNMENT, and show that CENTERING provides constraints on when a ZERO can be interpreted as the ZERO TOPIC

...scourse entities (Grosz et al., 1986). Centering has its computational foundations in the work of Grosz and Sidner (Grosz, 1977; Sidner, 1979) and was further developed by Grosz, Joshi and Weinstein (=-=Joshi and Kuhn, 1979-=-; Grosz et al., 1983; Grosz et al., 1986; Joshi and Weinstein, 1981). Centering is intended to reflect aspects of ATTENTIONAL STATE in a tripartite view of discourse structure that also includes INTEN...

"... Centering Theory is the best known framework for theorizing about local coherence and salience; however, its claims are articulated in terms of notions which are only partially specified, such as ‘utterance’, ‘realization’, or ‘ranking’. A great deal of research has attempted to arrive at more detai ..."

Centering Theory is the best known framework for theorizing about local coherence and salience; however, its claims are articulated in terms of notions which are only partially specified, such as ‘utterance’, ‘realization’, or ‘ranking’. A great deal of research has attempted to arrive at more detailed specifications of these PARAMETERS of the theory; as a result, the claims of Centering can be INSTANTIATED in many different ways. We investigated in a systematic fashion the effect of these different ways of setting the parameters on the theory’s claims. Doing this required, first of all, to clarify what the theory’s claims are (one of our conclusions being that what has become known as ’Constraint 1 ’ is actually a central claim of the theory). Secondly, we had to clearly identify these parametric aspects: e.g., we argue that the notion of ‘pronoun ’ used in Rule 1 should be considered a parameter. Thirdly, we had to find appropriate methods for evaluating these claims. We found that while the theory’s main claim about salience and pronominalization, Rule 1–a preference for pronominalizing the CB–is verified with most instantiations, Constraint 1–a claim about (entity) coherence and CB uniqueness–is much more instantiation-dependent: it is not verified if the parameters are instantiated according to very mainstream views (‘Vanilla instantiation’), it only holds if indirect realization is allowed, and is violated by between 20

...ous utterance: the ‘Backward-Looking Center’, or CB. Having a unique CB, it is claimed, considerably simplifies the complexity of the inferences required to integrate an utterance into the discourse (=-=Joshi and Kuhn, 1979-=-; Joshi and Weinstein, 1981). Centering’s first contention as far as local salience is concerned is that the discourse entities ’realized’ by an utterance (more on ’realization’ below) are ranked: i.e...

"... Abstract. In this paper the Centering model of anaphora resolution and discourse coherence (Grosz, Joshi and Weinstein, 1983, 1995) is reformulated in terms of Optimality Theory (ot) (Prince and Smolensky 1993). One version of the reformulated model is proven to be descriptively equivalent to an ear ..."

Abstract. In this paper the Centering model of anaphora resolution and discourse coherence (Grosz, Joshi and Weinstein, 1983, 1995) is reformulated in terms of Optimality Theory (ot) (Prince and Smolensky 1993). One version of the reformulated model is proven to be descriptively equivalent to an earlier algorithmic statement of Centering due to Brennan, Friedman and Pollard (1987). However, the new model is stated declaratively, and makes clearer the status of the various constraints used in the theory. In the second part of the paper, the model is extended, demonstrating the advantages of the ot reformulation, and capturing formally ideas originally described by Grosz, Joshi and Weinstein. Three new applications of the extended ot Centering model are described: generation of linguistic forms from meanings, the evaluation and optimization of extended texts, and the interpretation of accented pronouns.

"... We present an implementation of a discourse parsing system for a lexicalized Tree-Ajoining Grammar for discourse, specifying the integration of sentence and discourse level processing. Our system is based on the assumption that the compositional aspects of semantics at the discourse-level parallel t ..."

We present an implementation of a discourse parsing system for a lexicalized Tree-Ajoining Grammar for discourse, specifying the integration of sentence and discourse level processing. Our system is based on the assumption that the compositional aspects of semantics at the discourse-level parallel those at the sentence-level. This coupling is achieved by factoring away inferential semantics and anaphoric features of discourse connectives. Computationally, this parallelism is achieved because both the sentence and discourse grammar are LTAG-based and the same parser works at both levels. The approach to an LTAG for discourse has been developed by Webber et al. in some recent papers ([33], [35], among others). Our system takes a discourse as input, parses the sentences individually, extracts the basic discourse consituent units from the sentence derivations, and reparses the discourse with reference to the discourse grammar while using the same parser used at the sentence-level.

...h light on those aspects of structural organization that are relevant to language structure and presumably contribute to the eciency of the inferencing processes required for discourse interpretation =-=[10-=-]. Predicates whichsnd their arguments structurally dene a domain of locality for structural dependencies and constrain the interpretation of discourse in a computationally ecient way, as is the case ...

"... The purpose of this study is to explore an aspect of discourse coherence which involves anaphoric relations between utterances with special emphasis on subjects in Turkish. Based on an analysis of published narratives, three complementary and interrelated questions are addressed concerning discours ..."

The purpose of this study is to explore an aspect of discourse coherence which involves anaphoric relations between utterances with special emphasis on subjects in Turkish. Based on an analysis of published narratives, three complementary and interrelated questions are addressed concerning discourse anaphora: 1. Which expressions are available for subsequent definite reference? 2. What factors determine the most salient entity in Turkish among a set of potential antecedents for subsequent definite reference? 3. What are the functions of a particular referential expression (null vs. overt pronouns vs. full NPs), depending on appropriate discourse conditions? An exploration regarding question 1 indicates that, while some NPs evoke discourse entities, other NPs do not. These two types of NPs represent referential and nonreferential expressions and they can function as ...

...osz and Sidner 1986:180). Such a cognitive system is capable of complex inferencing. Attempting to model this complex inference system for pronoun resolution is not manageable at this stage. However, =-=Joshi and Kuhn 1979-=- and Joshi and Weinstein 1981 suggest that the inferencing required for discourse processing and for anaphora resolution can be constrained via centering notions. These suggestions are elaborated in G...

Existing software systems for automated essay scoring can provide NLP researchers with opportunities to test certain theoretical hypotheses, including some derived from Centering Theory. In this study we employ the Educational Testing Service’s e-rater essay scoring system to examine whether local discourse coherence, as defined by a measure of Centering Theory’s Rough-Shift transitions, might be a significant contributor to the evaluation of essays. Rough-Shifts within students ’ paragraphs often occur when topics are short-lived and unconnected, and are therefore indicative of poor topic development. We show that adding the Rough-Shift based metric to the system improves its performance significantly, better approximating human scores and providing the capability of valuable instructional feedback to the student. These results indicate that Rough-Shifts do indeed capture a source of incoherence, one that has not been closely examined in the Centering literature. They not only justify Rough-Shifts as a valid transition type, but they also support the original formulation of Centering as a measure of discourse continuity even in pronominal-free text. Finally, our study design, which used a combination of automated and manual NLP techniques, highlights specific areas of NLP research and development needed for engineering practical applications. 1

...re to e-rater’s existing array of features. 3 Overview of centering Two different lines of work were mainly responsible for the development of Centering Theory. Originally, Joshi, Kuhn and Weinstein (=-=Joshi and Kuhn 1979-=-; Joshi and Weinstein 1981) proposed Centering as a model of the complexity of inferencing involved in discourse when speakers process the meaning of an utterance and integrate it into the meaning of ...

"... SRI International I present a unified account of interpretation preferences of stressed and unstressed pronouns in discourse. The central intuition is the Complementary Preference Hypothesis that predicts the interpretation preference of a stressed pronoun from that of an unstressed pronoun in the s ..."

SRI International I present a unified account of interpretation preferences of stressed and unstressed pronouns in discourse. The central intuition is the Complementary Preference Hypothesis that predicts the interpretation preference of a stressed pronoun from that of an unstressed pronoun in the same discourse position. The base preference must be computed in a total pragmatics module including commonsense preferences. The focus constraint in Rooth’s theory of semantic focus is interpreted to be the salient subset of the domain in the local attentional state in the discourse context independently motivated for other purposes in Centering Theory. 1

"... An account of utterance interpretation in discourse needs to face the issue of how the discourse context controls the space of interacting preferences. Assuming a discourse processing architecture that distinguishes ..."

An account of utterance interpretation in discourse needs to face the issue of how the discourse context controls the space of interacting preferences. Assuming a discourse processing architecture that distinguishes

...3% for resolving pronouns in a variety of stories — of which only 12% relied on commonsense inferences. Grammar’s role in the control of inferences was the original motivation of the centering model (=-=Joshi and Kuhn, 1979-=-; Joshi and Weinstein, 1981). The proposal was to use the monadic tendency of discourse (i.e., tendency to be centrally about one thing at a time) to control the amount of computation required in disc...